TY - JOUR
T1 - MTrasT24, a metallothionein-ras fusion gene, modulates expression in cultured rat liver cells of two genes associated with in vivo liver cancer.
AU - Li, Y. C.
AU - Seyama, T.
AU - Godwin, A. K.
AU - Winokur, T. S.
AU - Lebovitz, R. M.
AU - Lieberman, M. W.
PY - 1988/1
Y1 - 1988/1
N2 - We studied the effects of a zinc-inducible metallothionein-ras fusion gene (MTrasT24) in cultured rat liver epithelial (RLE) cells on expression of two genes induced during liver carcinogenesis in vivo: gamma-glutamyltransferase [(5-glutamyl)-peptide:amino acid 5-glutamyltransferase, EC 2.3.2.2] and glutathione S-transferase-P (RX:glutathione R-transferase, EC 2.5.1.18). Expression of MTrasT24 increased steady-state RNA levels of gamma-glutamyltransferase and glutathione transferase-P 6- to 100-fold and 1.6- to 6-fold, respectively; in contrast, levels of alpha-tubulin RNA fell slightly or were unchanged. RNA gel blots verified that gamma-glutamyltransferase and glutathione transferase-P RNAs were of the appropriate size, and results from immunocytochemistry on transfected cells demonstrated that RLE cells carrying MTrasT24 synthesized immunoreactive, appropriately localized gamma-glutamyltransferase and glutathione transferase-P. Zinc induction studies indicated that gamma-glutamyltransferase and glutathione transferase-P RNA levels were directly dependent on MTrasT24 RNA levels. These data suggest that expression of gamma-glutamyltransferase and glutathione transferase-P expression are part of a reorientation of cellular gene expression during carcinogenesis and that activated ras expression, like chemical carcinogens, can bring about this change.
AB - We studied the effects of a zinc-inducible metallothionein-ras fusion gene (MTrasT24) in cultured rat liver epithelial (RLE) cells on expression of two genes induced during liver carcinogenesis in vivo: gamma-glutamyltransferase [(5-glutamyl)-peptide:amino acid 5-glutamyltransferase, EC 2.3.2.2] and glutathione S-transferase-P (RX:glutathione R-transferase, EC 2.5.1.18). Expression of MTrasT24 increased steady-state RNA levels of gamma-glutamyltransferase and glutathione transferase-P 6- to 100-fold and 1.6- to 6-fold, respectively; in contrast, levels of alpha-tubulin RNA fell slightly or were unchanged. RNA gel blots verified that gamma-glutamyltransferase and glutathione transferase-P RNAs were of the appropriate size, and results from immunocytochemistry on transfected cells demonstrated that RLE cells carrying MTrasT24 synthesized immunoreactive, appropriately localized gamma-glutamyltransferase and glutathione transferase-P. Zinc induction studies indicated that gamma-glutamyltransferase and glutathione transferase-P RNA levels were directly dependent on MTrasT24 RNA levels. These data suggest that expression of gamma-glutamyltransferase and glutathione transferase-P expression are part of a reorientation of cellular gene expression during carcinogenesis and that activated ras expression, like chemical carcinogens, can bring about this change.
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U2 - 10.1073/pnas.85.2.344
DO - 10.1073/pnas.85.2.344
M3 - Article
C2 - 2893374
AN - SCOPUS:0023781849
VL - 85
SP - 344
EP - 348
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 2
ER -